Unloader for compressors.



R. CONRADER. UNLOADER FOR COMPRESSORS. APPLICATION- FILED MAY 4. i915.

Patented Sept. 11, 1917 RUDOLPH CONRADER, OF ERIE, PENNSYLVANIA.

UN LOADER FOR COlllIIElESSOItS.

Specicat on of Letters Patent.

Patented dept. 111. 191W.

Application led May 4, 1915. 'Serial No. 25,855.

To ad who/a 1i may concern.'

lie it known that l, llunonru Commune, a citizen of the United States,residing at lflrie, in the county of Erie and State of Pennsylvania,have invented new and usel'ul Improvements in Unloaders forUoinpressors, of which the following is a specilication.

'lhis invention relates to unloadeis for compressors and consists incertain improvements in the construction thereof as will be hereinafterfully described and .pointed out in the claims. '-1' More particularlythe invention. reates toiniprovements ot' the unloader described inpatent issued to 111e June 225th, i910, #962,551.

The invention is illustrated in the accompanying drawing which shows acentral sec tion oi' the uuloader.

1 marks the body oi' .the` valve, 2 the dia- )hra un havino' the valve o)enin and seat n l a scribed operates as an intensifier a tti 3 thevalve, -l and 5 the inlet and discharge ends of the valve, either endmay be the inlet. A l'ranie extends from thebody l and a cylinder 7 isarranged in this frame. A piston 8 operates in the cylinder 7 and isconnected with the valve by means of a stem l). The stem extends througha spider or plate 10 havingopenings so that the shell or frame G andcylinder 7 are in c0mnnu1i-cation with one end. A spring 1l is arrangedaround the stem '9 :between theplate 10 and a shoulder on the stem.

A receiver connection 1Q leads to `the cylinder 13. .il piston 1l iscylinder 13. Its movement under pressure is opposed by a spring 15 andthe spring 15 may loe adjusted by a screw 16. The piston carries aneedle valve 17 operating in a passage 18. The passage 18 leads to theintensifying chamber 19 from which leads a lninute opening 20. Thedevice ust (ileong the manner described in my `former patent. Slightvariations :of receiver pressure move the piston 14 giving to the needlevalve 17 various degrees of opening. With a slight opening of thevneedle valve the escapef'of air through the minute opening is .such ast'o make a low pressure in the intensi-fying chamber'somewhat `aboveatmosphere. As the opening past the needle valve is increased it reachesa point where the opening 20 has little influence on the total pressureso that approximately receiver pressure will arranged in the'- Abedelivered to the intensifying chamber under these conditions. rlhisgives a Wide range of pressure in the intensifying chainber for a smallvariation of pressure in the receiver.

In my former structure, the `airn'as delivered lo the 'intensifierdirectly on the piston 8. In that device the air was passed through thevalve either from theend 5 when an abrupt closing was desired or fromthe end .1. when a regulating eti'ect was desired. instance, with lowpressure, it may be desirable to have an abrupt closing but 'where thedevice of my former patent was used, when the valve 3 closed the`atmospheric pressure alone on the valve with nearly a vacuum under thevalve was sufficient `to retard the opening of the valve before .thepressure in the cylinder 7 was reduced prac tically .to atmosphericpressure, the reason for this being that the spring 11 cannot he ofgreater strength .or stiffness than can he operated by the air `on thepiston 3. The air discharging from the piston 7 through the minuteopening 20 is very slow and where a nice regulation especially with asmall receiver is required interferes with the nice regulation ofpressure. This is true where either the end 4 or the `end .5 is used, asan inlet. g

ln the present invention I introduce an `intermediate pressurecontrolled valve 22. This is arranged in a cylinder 23. The cylinder 23is connected with `the intensifying chamber 19 by a passage 31 so thatthe pressure 4of ythe intensifying chandler is delivered to one end of`the valve 22. A spring 24 opposes the .movement of the valve 22 `andthe spring may he adjusted by 4a `screw The passage n26 connects thecylinder 23 with the cylinder 7. The valve 22 has a central way 27 whichnormally communicates with the passage 26. The exhaust passage 2E leadsfrom the cylinder 423 `and thspassage `is 4normally in communicationwith the Way 27. The exhaust passage is open `tothe ratmosphere and thesize .of `the open ng may be adjusted `by a screw 29.

In :the operation of the device `when 'the receiver pressure reaches thedesired amount it begins to open lthe valve 17. As the presa sureaccumulates in vthe intensifying chamloer 19 and the receiver pressureincreases, the pressure lon the valve l22 finally becomes sucient tomove the valve, 22 suciently to Under some circumstances, as fen @lllmit

rea

uncover the passage 26. This movement; closes off the passage QG fromthe way 2T. As soon as the passage "lf3 is uncovered air is delivereddirectly to the piston 8 and the valve is 4Icl'os'ed.- 'Vhen thepressure diminishes so as to permit the valve Q2 'to close, the passage26 is brought into communication ,withthe way The enlargedexhaustpassugev permits of the .immediate exhaust from the cylinder 8 soas to effect theopening of the valve 3.

lVhat I claim as new is :w

1. Inl ani unloader for compressors, the combinatio'nof` a valve bodyhaving inlet and discharg'ef openings and a valve seat therein; a val-veoperating on said seat; a fluid actuated motorcontrolling said valve; apressureactuated valve controlling said motorga cylinder in'vvhich thepressure actuated valveoperatesfsaid cylinder having an finlet port,admitting fluid 'to the end of lthe valve. and-subjecting `the valve tothe pressure'l'therefrom;- a portV leading to the fluid actuated motorand tlxeexhaust port, said port leading to thefluid actuated motor beingcovered by the valve as it is operated and'being connected as the valveis operated with either the inlet port or the exhaust port;counterpressu're means opposing the movement of the valve; a needlevalve controlling 'sai'd inlet port; and a pressure m'otor controllingsaid needle valve.

2. In an unload'er for compressors, the

combination of a` valve body having inlet and discharge/openings; and avalve seat; a relief valve opening and closing by a movement toward andfrom its seat; a fluid actuated motor controlling said valve; a pressureactuated valve controlling said motor,

said valve having'a pressure passage and an f macteo i exhaust passagecontrolled' by the. valve; and an intensifier connected with saidpressure actuated valve and controlling the delivery of air to saidpressure actuated valve said intensifier comprising a chamber; agradually opening needle valve controlling the admission of fluid tosaid'chamber; and

a minute discharge opening from 'said cham-Y ber. .n

3. In an unloader for. compressors, the

Acombinationhof a valve body having inlet and discharge openings and avalve seat therein; la valve operating on said seat; av

fluid actuated motor controlling said valve;

a pressure actiiated valve controlling said motor; a cylinder inwhiehthe pressure actuated valve operates, said cylinder having an inletport' admitting fluid to the end of the valve and subjecting the valveto the pressure therefrom;'a port leading to the Ifluid actuated motor;and an exhaust port,

said port leading to the fluid actuated motor being covered by the valveas'it is operated and being connected as the valve is operated witheither the inlet port or the exhaust port; counter-pressure meansopposing the movement of the valve; and an intensifier controlling themovement of air to the inlet port, said intensifier comprising achamber; a gradually opening needle valve controlling the movement offluid to the chamber; and a minute discharge opening.' leading from thechamber. i*

In testimony whereof Ihave hereunto se 7a my hand in the presence of twosubscribing witnesses.

RUDOLPH CONRDER.

Witnesses:

H. o. LORD, B. M. HARTMAN.

